There is widely used a method in which an element-group formation substrate made by forming plural electronic elements on a substrate is divided and cut into pieces, thereby obtaining plural element chips.
As a conventional art described in an official gazette, there is a technique in which, in order to separate semiconductor light emitting elements formed on a substrate, pulse laser is collected to a predetermined depth inside of the substrate to form internal modified portions that are not continuous in a direction of a line to be separated, and the internal modified portions are made more than two stages in the depth direction of the substrate (see Patent Literature 1).